include/QtCore/qstringconverter_base.h

0001 // Copyright (C) 2022 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003 // Qt-Security score:critical reason:data-parser
0004
0005 #ifndef QSTRINGCONVERTER_BASE_H
0006 #define QSTRINGCONVERTER_BASE_H
0007
0008 #if 0
0009 // IWYU pragma: private, include "qstringconverter.h"
0010 // QStringConverter(Base) class are handled in qstringconverter
0011 #pragma qt_sync_stop_processing
0012 #endif
0013
0014 #include <optional>
0015
0016 #include <QtCore/qglobal.h> // QT_{BEGIN,END}_NAMESPACE
0017 #include <QtCore/qflags.h> // Q_DECLARE_FLAGS
0018 #include <QtCore/qcontainerfwd.h>
0019 #include <QtCore/qstringfwd.h>
0020
0021 #include <cstring>
0022
0023 QT_BEGIN_NAMESPACE
0024
0025 class QByteArrayView;
0026 class QChar;
0027 class QByteArrayView;
0028 class QStringView;
0029
0030 #if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) && !defined(Q_QDOC) && !defined(QT_BOOTSTRAPPED)
0031 class QStringConverterBase
0032 #else
0033 class QStringConverter
0034 #endif
0035 {
0036 public:
0037     enum class Flag {
0038         Default = 0,
0039         Stateless = 0x1,
0040         ConvertInvalidToNull = 0x2,
0041         WriteBom = 0x4,
0042         ConvertInitialBom = 0x8,
0043         UsesIcu = 0x10,
0044     };
0045     Q_DECLARE_FLAGS(Flags, Flag)
0046
0047     struct State {
0048         constexpr State(Flags f = Flag::Default) noexcept
0049             : flags(f), state_data{0, 0, 0, 0} {}
0050         ~State() { clear(); }
0051
0052         State(State &&other) noexcept
0053             : flags(other.flags),
0054               remainingChars(other.remainingChars),
0055               invalidChars(other.invalidChars),
0056               state_data{other.state_data[0], other.state_data[1],
0057                          other.state_data[2], other.state_data[3]},
0058               clearFn(other.clearFn)
0059         { other.clearFn = nullptr; }
0060         State &operator=(State &&other) noexcept
0061         {
0062             clear();
0063             flags = other.flags;
0064             remainingChars = other.remainingChars;
0065             invalidChars = other.invalidChars;
0066             std::memmove(state_data, other.state_data, sizeof state_data); // self-assignment-safe
0067             clearFn = other.clearFn;
0068             other.clearFn = nullptr;
0069             return *this;
0070         }
0071         Q_CORE_EXPORT void clear() noexcept;
0072         Q_CORE_EXPORT void reset() noexcept;
0073
0074         Flags flags;
0075         int internalState = 0;
0076         qsizetype remainingChars = 0;
0077         qsizetype invalidChars = 0;
0078
0079         union {
0080             uint state_data[4];
0081             void *d[2];
0082         };
0083         using ClearDataFn = void (*)(State *) noexcept;
0084         ClearDataFn clearFn = nullptr;
0085     private:
0086         Q_DISABLE_COPY(State)
0087     };
0088
0089 #if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) && !defined(Q_QDOC) && !defined(QT_BOOTSTRAPPED)
0090 protected:
0091     QStringConverterBase() = default;
0092     ~QStringConverterBase() = default;
0093     QStringConverterBase(QStringConverterBase &&) = default;
0094     QStringConverterBase &operator=(QStringConverterBase &&) = default;
0095 };
0096
0097 class QStringConverter : public QStringConverterBase
0098 {
0099 public:
0100 #endif // Qt 6 compat for QStringConverterBase
0101
0102     enum Encoding {
0103         Utf8,
0104 #ifndef QT_BOOTSTRAPPED
0105         Utf16,
0106         Utf16LE,
0107         Utf16BE,
0108         Utf32,
0109         Utf32LE,
0110         Utf32BE,
0111 #endif
0112         Latin1,
0113         System,
0114         LastEncoding = System
0115     };
0116
0117 protected:
0118
0119     struct Interface
0120     {
0121         using DecoderFn = QChar * (*)(QChar *out, QByteArrayView in, State *state);
0122         using LengthFn = qsizetype (*)(qsizetype inLength);
0123         using EncoderFn = char * (*)(char *out, QStringView in, State *state);
0124         const char *name = nullptr;
0125         DecoderFn toUtf16 = nullptr;
0126         LengthFn toUtf16Len = nullptr;
0127         EncoderFn fromUtf16 = nullptr;
0128         LengthFn fromUtf16Len = nullptr;
0129     };
0130
0131     constexpr QStringConverter() noexcept
0132         : iface(nullptr)
0133     {}
0134     constexpr explicit QStringConverter(Encoding encoding, Flags f)
0135         : iface(&encodingInterfaces[qsizetype(encoding)]), state(f)
0136     {}
0137     constexpr explicit QStringConverter(const Interface *i) noexcept
0138         : iface(i)
0139     {}
0140 #if QT_CORE_REMOVED_SINCE(6, 8)
0141     Q_CORE_EXPORT explicit QStringConverter(const char *name, Flags f);
0142 #endif
0143     Q_CORE_EXPORT explicit QStringConverter(QAnyStringView name, Flags f);
0144
0145
0146     ~QStringConverter() = default;
0147
0148 public:
0149     QStringConverter(QStringConverter &&) = default;
0150     QStringConverter &operator=(QStringConverter &&) = default;
0151
0152     bool isValid() const noexcept { return iface != nullptr; }
0153
0154     void resetState() noexcept
0155     {
0156         state.reset();
0157     }
0158     bool hasError() const noexcept { return state.invalidChars != 0; }
0159
0160     Q_CORE_EXPORT const char *name() const noexcept;
0161
0162 #if QT_CORE_REMOVED_SINCE(6, 8)
0163     Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name) noexcept;
0164 #endif
0165     Q_CORE_EXPORT static std::optional<Encoding> encodingForName(QAnyStringView name) noexcept;
0166     Q_DECL_PURE_FUNCTION Q_CORE_EXPORT static const char *nameForEncoding(Encoding e) noexcept;
0167     Q_CORE_EXPORT static std::optional<Encoding>
0168     encodingForData(QByteArrayView data, char16_t expectedFirstCharacter = 0) noexcept;
0169     Q_CORE_EXPORT static std::optional<Encoding> encodingForHtml(QByteArrayView data);
0170
0171     Q_CORE_EXPORT static QStringList availableCodecs();
0172
0173
0174     enum class FinalizeResultError : quint8 {
0175         NoError,
0176         InvalidCharacters,
0177         NotEnoughSpace,
0178     };
0179     template <typename Char>
0180     struct FinalizeResultChar
0181     {
0182         using Error = FinalizeResultError;
0183
0184         Char *next;
0185         qint16 invalidChars;
0186         Error error;
0187     };
0188
0189 protected:
0190     const Interface *iface;
0191     State state;
0192 private:
0193     Q_CORE_EXPORT static const Interface encodingInterfaces[Encoding::LastEncoding + 1];
0194 };
0195
0196 Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverter::Flags)
0197
0198 QT_END_NAMESPACE
0199
0200 #endif